<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <h1>我是一个h5页面</h1>
    <img src="">
    <button onclick="">打开相册</button>
    <button onclick="changeText()">修改p标签内容</button>

</body>

<script>
    function changeText(str="我是默认值"){
        document.querySelector('p').innerHTML = '真爽啊'
    }

    function selOpenPhoto(){
        objName.objKey(2)
    }
</script>
</html>